package com.ichi2.themes;

import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class HtmlColors {
    private static final Pattern fHtmlColorPattern = Pattern.compile(
            "((?:color|background)\\s*[=:]\\s*\"?)((?:[a-z]+|#[0-9a-f]+|rgb\\([0-9]+,\\s*[0-9],+\\s*[0-9]+\\)))([\";\\s])", Pattern.CASE_INSENSITIVE);
    private static final Pattern fShortHexColorPattern = Pattern.compile("^#([0-9a-f])([0-9a-f])([0-9a-f])$", Pattern.CASE_INSENSITIVE);
    private static final Pattern fLongHexColorPattern = Pattern.compile("^#([0-9a-f]{2})([0-9a-f]{2})([0-9a-f]{2})$", Pattern.CASE_INSENSITIVE);
    private static final Pattern fRgbColorPattern = Pattern.compile("^rgb\\(([0-9]+)\\s*,\\s*([0-9]+)\\s*,\\s*([0-9]+)\\)$", Pattern.CASE_INSENSITIVE);
    private static final Pattern fClozeStylePattern = Pattern.compile("(.cloze\\s*\\{[^}]*color:\\s*#)[0-9a-f]{6}(;[^}]*\\})", Pattern.CASE_INSENSITIVE);
    private static final Pattern fDiffStylePattern = Pattern.compile("");

    public static String nameToHex(String name) {
        if (sColorsMap == null) {
            sColorsMap = new HashMap<>();
            for (int i = 0; i < fColorsRawList.length; i+=2) {
                sColorsMap.put(fColorsRawList[i].toLowerCase(Locale.US), fColorsRawList[i+1].toLowerCase(Locale.US));
            }
        }
        name = name.toLowerCase(Locale.US);
        if (sColorsMap.containsKey(name)) {
            return sColorsMap.get(name);
        }
        return name;
    }
    /**
     * Returns a string where all colors have been inverted. It applies to anything that is in a tag and looks like
     * #FFFFFF Example: Here only #000000 will be replaced (#777777 is content) <span style="color: #000000;">Code
     * #777777 is the grey color</span> This is done with a state machine with 2 states: - 0: within content - 1: within
     * a tag
     */
    public static String invertColors(String text) {
        StringBuffer sb = new StringBuffer();
        Matcher m1 = fHtmlColorPattern.matcher(text);
        while (m1.find()) {
            // Convert names to hex
            String color = HtmlColors.nameToHex(m1.group(2));
            Matcher m2 = null;
            try {
                if (color.length() == 4 && color.charAt(0) == '#') {
                    m2 = fShortHexColorPattern.matcher(color);
                    if (m2.find()) {
                        color = String.format(Locale.US, "#%x%x%x",
                                0xf - Integer.parseInt(m2.group(1), 16),
                                0xf - Integer.parseInt(m2.group(2), 16),
                                0xf - Integer.parseInt(m2.group(3), 16));
                    }
                } else if (color.length() == 7 && color.charAt(0) == '#') {
                    m2 = fLongHexColorPattern.matcher(color);
                    if (m2.find()) {
                        color = String.format(Locale.US, "#%02x%02x%02x",
                                0xff - Integer.parseInt(m2.group(1), 16),
                                0xff - Integer.parseInt(m2.group(2), 16),
                                0xff - Integer.parseInt(m2.group(3), 16));
                    }
                } else if (color.length() > 9 && color.toLowerCase(Locale.US).startsWith("rgb")) {
                    m2 = fRgbColorPattern.matcher(color);
                    if (m2.find()) {
                        color = String.format(Locale.US, "rgb(%d, %d, %d)",
                                0xff - Integer.parseInt(m2.group(1)),
                                0xff - Integer.parseInt(m2.group(2)),
                                0xff - Integer.parseInt(m2.group(3)));
                    }
                }
            } catch (NumberFormatException e) {
                // shouldn't happen but ignore anyway
            }
            m1.appendReplacement(sb, m1.group(1) + color + m1.group(3));
        }
        m1.appendTail(sb);
        String invertedText = sb.toString();
        // fix style for cloze to light blue instead of inverted blue which ends up as yellow
        Matcher mc = fClozeStylePattern.matcher(invertedText);
        invertedText = mc.replaceAll("$10088ff$2");

        return invertedText;
    }

    private static Map<String, String> sColorsMap = null;
    private static final String[] fColorsRawList= new String[]{
    "AliceBlue", "#F0F8FF",
    "AntiqueWhite", "#FAEBD7",
    "Aqua", "#00FFFF",
    "Aquamarine", "#7FFFD4",
    "Azure", "#F0FFFF",
    "Beige", "#F5F5DC",
    "Bisque", "#FFE4C4",
    "Black", "#000000",
    "BlanchedAlmond", "#FFEBCD",
    "Blue", "#0000FF",
    "BlueViolet", "#8A2BE2",
    "Brown", "#A52A2A",
    "BurlyWood", "#DEB887",
    "CadetBlue", "#5F9EA0",
    "Chartreuse", "#7FFF00",
    "Chocolate", "#D2691E",
    "Coral", "#FF7F50",
    "CornflowerBlue", "#6495ED",
    "Cornsilk", "#FFF8DC",
    "Crimson", "#DC143C",
    "Cyan", "#00FFFF",
    "DarkBlue", "#00008B",
    "DarkCyan", "#008B8B",
    "DarkGoldenRod", "#B8860B",
    "DarkGray", "#A9A9A9",
    "DarkGrey", "#A9A9A9",
    "DarkGreen", "#006400",
    "DarkKhaki", "#BDB76B",
    "DarkMagenta", "#8B008B",
    "DarkOliveGreen", "#556B2F",
    "Darkorange", "#FF8C00",
    "DarkOrchid", "#9932CC",
    "DarkRed", "#8B0000",
    "DarkSalmon", "#E9967A",
    "DarkSeaGreen", "#8FBC8F",
    "DarkSlateBlue", "#483D8B",
    "DarkSlateGray", "#2F4F4F",
    "DarkSlateGrey", "#2F4F4F",
    "DarkTurquoise", "#00CED1",
    "DarkViolet", "#9400D3",
    "DeepPink", "#FF1493",
    "DeepSkyBlue", "#00BFFF",
    "DimGray", "#696969",
    "DimGrey", "#696969",
    "DodgerBlue", "#1E90FF",
    "FireBrick", "#B22222",
    "FloralWhite", "#FFFAF0",
    "ForestGreen", "#228B22",
    "Fuchsia", "#FF00FF",
    "Gainsboro", "#DCDCDC",
    "GhostWhite", "#F8F8FF",
    "Gold", "#FFD700",
    "GoldenRod", "#DAA520",
    "Gray", "#808080",
    "Grey", "#808080",
    "Green", "#008000",
    "GreenYellow", "#ADFF2F",
    "HoneyDew", "#F0FFF0",
    "HotPink", "#FF69B4",
    "IndianRed", "#CD5C5C",
    "Indigo", "#4B0082",
    "Ivory", "#FFFFF0",
    "Khaki", "#F0E68C",
    "Lavender", "#E6E6FA",
    "LavenderBlush", "#FFF0F5",
    "LawnGreen", "#7CFC00",
    "LemonChiffon", "#FFFACD",
    "LightBlue", "#ADD8E6",
    "LightCoral", "#F08080",
    "LightCyan", "#E0FFFF",
    "LightGoldenRodYellow", "#FAFAD2",
    "LightGray", "#D3D3D3",
    "LightGrey", "#D3D3D3",
    "LightGreen", "#90EE90",
    "LightPink", "#FFB6C1",
    "LightSalmon", "#FFA07A",
    "LightSeaGreen", "#20B2AA",
    "LightSkyBlue", "#87CEFA",
    "LightSlateGray", "#778899",
    "LightSlateGrey", "#778899",
    "LightSteelBlue", "#B0C4DE",
    "LightYellow", "#FFFFE0",
    "Lime", "#00FF00",
    "LimeGreen", "#32CD32",
    "Linen", "#FAF0E6",
    "Magenta", "#FF00FF",
    "Maroon", "#800000",
    "MediumAquaMarine", "#66CDAA",
    "MediumBlue", "#0000CD",
    "MediumOrchid", "#BA55D3",
    "MediumPurple", "#9370D8",
    "MediumSeaGreen", "#3CB371",
    "MediumSlateBlue", "#7B68EE",
    "MediumSpringGreen", "#00FA9A",
    "MediumTurquoise", "#48D1CC",
    "MediumVioletRed", "#C71585",
    "MidnightBlue", "#191970",
    "MintCream", "#F5FFFA",
    "MistyRose", "#FFE4E1",
    "Moccasin", "#FFE4B5",
    "NavajoWhite", "#FFDEAD",
    "Navy", "#000080",
    "OldLace", "#FDF5E6",
    "Olive", "#808000",
    "OliveDrab", "#6B8E23",
    "Orange", "#FFA500",
    "OrangeRed", "#FF4500",
    "Orchid", "#DA70D6",
    "PaleGoldenRod", "#EEE8AA",
    "PaleGreen", "#98FB98",
    "PaleTurquoise", "#AFEEEE",
    "PaleVioletRed", "#D87093",
    "PapayaWhip", "#FFEFD5",
    "PeachPuff", "#FFDAB9",
    "Peru", "#CD853F",
    "Pink", "#FFC0CB",
    "Plum", "#DDA0DD",
    "PowderBlue", "#B0E0E6",
    "Purple", "#800080",
    "Red", "#FF0000",
    "RosyBrown", "#BC8F8F",
    "RoyalBlue", "#4169E1",
    "SaddleBrown", "#8B4513",
    "Salmon", "#FA8072",
    "SandyBrown", "#F4A460",
    "SeaGreen", "#2E8B57",
    "SeaShell", "#FFF5EE",
    "Sienna", "#A0522D",
    "Silver", "#C0C0C0",
    "SkyBlue", "#87CEEB",
    "SlateBlue", "#6A5ACD",
    "SlateGray", "#708090",
    "SlateGrey", "#708090",
    "Snow", "#FFFAFA",
    "SpringGreen", "#00FF7F",
    "SteelBlue", "#4682B4",
    "Tan", "#D2B48C",
    "Teal", "#008080",
    "Thistle", "#D8BFD8",
    "Tomato", "#FF6347",
    "Turquoise", "#40E0D0",
    "Violet", "#EE82EE",
    "Wheat", "#F5DEB3",
    "White", "#FFFFFF",
    "WhiteSmoke", "#F5F5F5",
    "Yellow", "#FFFF00",
    "YellowGreen", "#9ACD32"};
}
